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Tytuł:
Laccase Immobilization on Biopolymer Carriers – Preliminary Studies
Autorzy:
Deska, Małgorzata
Kończak, Beata
Powiązania:
https://bibliotekanauki.pl/articles/2086365.pdf
Data publikacji:
2022
Wydawca:
Polskie Towarzystwo Inżynierii Ekologicznej
Tematy:
laccase
immobilization
biopolymer
biocatalysis
Opis:
This preliminary studies concerns preparation of biopolymer carriers for immobilization of laccase from Trametes versicolor, based on sodium alginate, chitosan and on a combined alginate-chitosan biopolymers as well as the evaluation of their potential use in the decolourization process. The study is related to the assessment the using of various carriers in the immobilization methods of laccase. The dropping method using sodium alginate (2%) proved to be the most effective technique of enzyme immobilization. The study showed an improvement in the stability of immobilized laccases under the conditions of variable pH, relative to a free laccase. A loss in the stability of enzymes in alginate beads occurs at high temperatures, together with enzyme leaching and degradation. Enzyme leaching from the beads inhibits their preliminary low-temperature drying. Immobilization and drying of obtained capsules constitutes a promising method for improving enzyme stability. The results obtained as part of this study offer a valuable contribution to the future research on the possibility of using the prepared alginate beads to remove colour contamination from wastewater.
Źródło:
Journal of Ecological Engineering; 2022, 23, 4; 235--249
2299-8993
Pojawia się w:
Journal of Ecological Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An organic solvent and surfactant stable α-amylase from soybean seeds
Autorzy:
Jaiswal, Nivedita
Prakash, Om
Powiązania:
https://bibliotekanauki.pl/articles/1039536.pdf
Data publikacji:
2013
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
agarose
agar
gelatin
biocatalysis
detergent
immobilization
Opis:
An organic solvent and surfactant stable α-amylase was obtained from soybean seeds. The direct and indirect effect of various organic solvents (non-polar, polar protic, and polar aprotic) and surfactants on the activity and stability of free enzyme was determined. The enzyme showed a very high catalytic efficiency and stabilization against most of the organic solvents and surfactants tested, except for few. Those organic solvents and surfactants (like chloroform, dimethyl formamide, n-butanol, and Tween 20), which caused an inhibition in enzyme activity, were used to study their effects on immobilized enzyme. The inhibitory effect was found to be decreased in immobilized enzyme as compared to free enzyme indicating that immobilization imparted stability to the enzyme. Moreover, the possibility of reuse of the enzyme in the presence of the organic solvents and surfactants was increased upon immobilization. The stability of soybean α-amylase towards organic solvents and surfactants shows that it is a potential candidate for use in organic-solvent biocatalysis as well as in detergent industries.
Źródło:
Acta Biochimica Polonica; 2013, 60, 3; 387-393
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Proces niskotemperaturowej biokatalizy na przykładzie grzybowej biotransformacji [alfa]-pinenu
Low-temperature biocatalysis as an example of microbial biotransformation of alpha-pinene
Autorzy:
Skowroński, J.
Trytek, M.
Fiedurek, J.
Powiązania:
https://bibliotekanauki.pl/articles/256660.pdf
Data publikacji:
2013
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Technologii Eksploatacji - Państwowy Instytut Badawczy
Tematy:
biokataliza
biotransformacja
drobnoustroje psychrotroficzne
biocatalysis
biotransformation
psychrotrophic microorganisms
Opis:
Katalizatory warunkują przebieg oraz odpowiednią wydajność wielu reakcji chemicznych. Przemiany biochemiczne w większości przypadków katalizowane są z udziałem enzymów. Szczególne cechy biokatalizatorów są powszechnie wykorzystywane w przemyśle, a w ostatnich latach drobnoustroje ekstremofilne, adaptowane do skrajnych warunków abiotycznych, wzbudzają duże zainteresowanie licznej grupy badaczy. Wyjątkowe predyspozycje biokatalizatora psychrotroficznego z dobrymi efektami zostały wykorzystane w procesie biotransformacji a-pinenu do werbenolu i werbenonu, będących cennymi związkami smakowo-zapachowymi stosowanymi w branży spożywczej i kosmetycznej. Uzyskane wyniki (sumaryczne stężenie produktów przekraczające 0,5 g/dm3) stanowią obiecującą perspektywę wykorzystania tego typu procesów w większej skali (ponadlaboratoryjnej).
Many chemical reactions and their appropriate performance depend on catalysis. Most biochemical reactions are catalysed by enzymes. Special features of these biocatalysts are commonly employed in industry and current researches are focused on psychrotrophic microorganisms. These unique organisms can be a rich source of useful biocatalysts for biotransformation of a-pinene to verbenol and verbenone - valuable compounds used as flavours and fragrances. Results obtained in this study are promising for further application in the large scale.
Źródło:
Problemy Eksploatacji; 2013, 1; 101-111
1232-9312
Pojawia się w:
Problemy Eksploatacji
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A new method for detecting cross-inhibition effects in the environmental biocatalytic processes
Autorzy:
Herke, Z.
Maskow, T.
Nemeth, Z.I.
Powiązania:
https://bibliotekanauki.pl/articles/80851.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
biocatalysis
microorganism
enzyme
bioremediation
inhibition
modelling
regression analysis
principal component analysis
Źródło:
BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology; 2015, 96, 4
0860-7796
Pojawia się w:
BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Microbial biotransformation of two phosphonoacetic acid derivatives bearing two stereomeric centres
Autorzy:
Szyszkowiak, J.
Majewska, P.
Powiązania:
https://bibliotekanauki.pl/articles/80546.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
biotransformation
Serratia liquefaciens
Bacillus subtilis
Escherichia coli
lipolytic activity
phosphonoacetic acid
biocatalysis
Opis:
Three strains of microorganisms: Bacillus subtilis, Serratia liquefaciens and Escherichia coli were tested as whole-cell biocatalysts for the kinetic resolution of isomers of two new phosphonoacetic acid derivatives. Used compounds possess two chiral centres – one at the carbon adjacent to both functional groups and the other at the phosphorus. Biocatalytic hydrolysis of 2-butyryloxy-2-(butoxyetoxyphosphinyl)acetic acid and 2-butyryloxy-2-(isobutoxyetoxyphosphinyl) acetic acid with whole cells of Bacillus subtilis produced corresponding hydroxyphosphonates with diastereoselectivity ranging from 50 to 60%.
Źródło:
BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology; 2013, 94, 4
0860-7796
Pojawia się w:
BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Biokatalizatory i biopolimery w aspekcie zrównoważonej chemii
Biocatalysts and biopolymers in the aspect of sustainable chemistry
Autorzy:
Jesionowski, Teofil
Klapiszewski, Łukasz
Zdarta, Jakub
Powiązania:
https://bibliotekanauki.pl/articles/1853728.pdf
Data publikacji:
2021
Wydawca:
Polskie Towarzystwo Chemiczne
Tematy:
zielona chemia
ochrona środowiska
biokataliza
biopolimery
green chemistry
environmental protection
biocatalysis
biopolymers
Opis:
The rapid development of industry, apart from the obvious benefits, also leads to a significant increase in the level of environmental pollution, which is related not only to the use of harmful substances in the production process, but also to the production of significant amounts of by-products and wastes, which pose a serious threat to the environment as well as to the health and the life of living organisms. There is therefore a need to limit the use of toxic substances at every stage of production, and where this is not possible, appropriate waste management and the development of effective methods of harmful substances removal. In this respect, it seems crucial to introduce the principles of Green Chemistry as widely as possible. Green Chemistry is a concept whose main assumptions focus on designing and conducting chemical processes in a way that minimizes the use and formation of harmful substances as much as possible. This staretgy is based on twelve principles that overlap with the main assumptions of environmental chemistry to improve environmental protection and reduce pollution. There are many techniques and methods that fit into the assumptions of the broadly understood Green Chemistry, the implementation of which allows for sustainable management of post-production waste and by-products as well as their effective disposal. One of such concepts assumes the use of waste substances as a valuable raw material, not only for energy, but above all as a precursor and/or component for the production of innovative materials with high utility potential. Another idea is the use of enzymes, i.e. natural biocatalysts that allow chemical transformations to be carried out under mild process conditions, without the need to use harmful solvents. What's more, enzymes can be used not only at the stage of conversion/synthesis of substrates, but they can also be efficient tools for removing harmful substances. Hence, it seems necessary to undertake attempts aimed at the widest possible management of waste substances, as well as conduct research, the effect of which is the production of functional biocatalytic systems for various applications.
Źródło:
Wiadomości Chemiczne; 2021, 75, 9-10; 1241-1267
0043-5104
2300-0295
Pojawia się w:
Wiadomości Chemiczne
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Bio-inspired trypsin-chitosan cross-linked enzyme aggregates: a versatile approach for stabilization through carrier-free immobilization
Autorzy:
Mageed, H.A.
Ezz, N.A.
Radwan, R.
Powiązania:
https://bibliotekanauki.pl/articles/80347.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
cross-linked enzyme aggregate
trypsin
free immobilization
chitosan
kinetic parameter
thermal stability
biocatalysis
Źródło:
BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology; 2019, 100, 3
0860-7796
Pojawia się w:
BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wpływ błony komórkowej na optymalne profile temperatury w procesie biotransformacji z równoległą dezaktywacją wewnątrzkomórkowego enzymu
Effect of cell membrane on optimal temperature profiles in the biotransformation with parallel endoenzyme deactivation
Autorzy:
Grubecki, I.
Powiązania:
https://bibliotekanauki.pl/articles/2073087.pdf
Data publikacji:
2015
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
biokataliza
efektywność
dezaktywacja biokatalizatora
optymalny profil temperatury
biocatalysis
effectiveness
biocatalyst deactivation
optimal temperature profile
Opis:
Rozważono okresowy proces biotransformacji przebiegający w obecności komórek drobnoustrojów wykazujących aktywność enzymu ulegającego dezaktywacji równoległej. W oparciu o klasyczną metodę rachunku wariacyjnego określono optymalne warunki temperaturowe zapewniające minimalny czas przebiegu procesu. Wykazano, że zastosowanie komórek drobnoustrojów spowalnia szybkość przebiegu rozkładu nadtlenku wodoru powodując przesunięcie początkowej temperatury profilów optymalnych w kierunku wyższych wartości. Przesuniecie to jest tym wyraźniejsze, im niższa jest przenikalność błony komórkowej. W konsekwencji obserwuje wydłużenie czasu przebiegu procesu optymalnego, przy czym dolne ograniczenie temperaturowe staje się nieaktywne.
A batch biotransformation process running in the presence of microorganisms cells revealing a specified enzyme activity was considered. The parallel deactivation of enzyme was taken into account. Based on variational calculus computations the optimal temperature conditions ensuring minimum duration time were determined. It was proved that the application of microorganisms cells results in slowing down the reaction rate and shifting the initial temperature of stationary profile to higher values. They are more pronounced when the lower is the permeability of membrane cell. In consequence, the extension of process duration time is observed along the sections of optimal profile while the lower temperature constraint usually becomes inactive
Źródło:
Inżynieria i Aparatura Chemiczna; 2015, 3; 87--89
0368-0827
Pojawia się w:
Inżynieria i Aparatura Chemiczna
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Przemysłowe zastosowania lipaz w syntezie związków o wysokiej wartości dodanej – 85 lat katalizy enzymatycznej lipazami. Część 2
Industrial applications of lipases in the synthesis of high added-value chemicals – 85 years of lipase-based enzymatic catalysis. Part 2
Autorzy:
Borowiecki, P.
Powiązania:
https://bibliotekanauki.pl/articles/172213.pdf
Data publikacji:
2015
Wydawca:
Polskie Towarzystwo Chemiczne
Tematy:
lipazy
zastosowania przemysłowe
biokataliza
związki enancjomerycznie czyste
lipases
industrial applications
biocatalysis
enantiomerically pure compounds
Opis:
Biotransformations are processes, in which chemical reactions are catalyzed by isolated enzymes or whole cells containing them. Among the biocatalysts, lipases are the most commonly used chiral selectors that exhibit high chemo-, regio-, and stereo-selectivity toward wide spectrum of organic compounds of xenobiothic nature. Moreover, lipases are very stable and active in organic solvents, as well as in neat solvents or in supercritical fluids in the absence of added water. Biotransformations by using lipases can be carried out at high substrate concentrations, at ambient temperature and neutral pH, without need for addition of cofactors, application of high pressures, extremely harsh reaction conditions or complex chemical apparatus. In addition, processes based on efficient biocatalytic technologies has proven to be beneficial for the chemical industry, as the lipases are able to catalyze reactions, which are not easily conducted by classical methods or in other cases allow reactions, which can replace several chemical steps. The above mentioned features of lipase-based biotransformations often cause significant improvement in energy efficiency (savings), and lead to a reduction in waste generation thereby making manufacturing processes even more economically attractive and environmentally acceptable. Since the mid-1980s the use of biotransformations with lipases in industry for the production of high added-value compounds, including pharmaceuticals, vitamins, cosmetics, fragrances and flavors, diagnostic preparations and therapeutics, high-tonnage preparation of agrochemicals, modified foods, nutraceuticals, detergents, polymers, advanced materials and biofuels has steadily increased. In this part of the review article on industrial applications of lipases, next group of popularly utilized enzymes relevant for the production of high added-value chemicals are described. It was also shown on several examples that enzymatic catalysis can significantly simplify manufacturing processes of complex structures being green and economical alternative for conventional chemical-based processes. Keywords:
Źródło:
Wiadomości Chemiczne; 2015, 69, 5-6; 431-463
0043-5104
2300-0295
Pojawia się w:
Wiadomości Chemiczne
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Zastosowania enzymów z tkanek zwierzęcych w syntezie organicznej i biokatalizie. Część I. Hydrolazy
Applications of hydrolases from animal tissues in organic synthesis
Autorzy:
Hibner, H.
Ostaszewski, R.
Powiązania:
https://bibliotekanauki.pl/articles/172016.pdf
Data publikacji:
2011
Wydawca:
Polskie Towarzystwo Chemiczne
Tematy:
enzymy zwierzęce
biokataliza
synteza organiczna
zastosowania hydrolaz
animal enzymes
biocatalysis
organic synthesis
applications of hydrolases
Opis:
This work presents systematically enzymes which can be obtained form animal tissue and their applications in synthesis of pharmaceuticals and nonracemic organic compounds. It lays out similarities in procedures of isolation and purification of particular enzymes. Such procedures usually are so simple that they can be used in every industrial or research laboratory. Most animal enzymes are well-investigated and their structures and substrate specificity are known. They are used as biocatalysts in many chemical processes. Others were used in one or a few reactions but their natural substrates and biochemical properties are described. Trials of predicting potential applications of such enzymes and other substrates for them were done. In this part typical applications of hydrolases: lipases (porcine pancreatic lipase [8–17], lamb pregastric lipase [22]), esterases (porcine, horse liver esterase, liver acetone powders [34–43, 46]), L-aminoacylase [48, 49], pepsin [56], trypsin [58, 59], imidase [52, 53], aldohexose hydrolases [60, 62-64], nucleotide pyrophosphatase [65]; were described. Also examples of immobilized [10, 32] or recombined [49] enzymes are given in the text. These modifications enhance catalytic properties or reduce costs of using enzymes. In practical applications a biocatalytic effect of enzymes from animal sources is often compared with microbial ones. This text is focused on processes where animal enzymes gave much better results (yield and enantioselectivity) than microorganisms. They are also proper, unlike whole microorganisms, to investigate and computer analysis of mechanism of the reaction. Enzymes isolated from animal tissues usually have well-defined structure of active site which is a key to predict mechanisms.
Źródło:
Wiadomości Chemiczne; 2011, 65, 7-8; 557-583
0043-5104
2300-0295
Pojawia się w:
Wiadomości Chemiczne
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Zastosowania wybranych enzymów z tkanek zwierzęcych w syntezie organicznej i biokatalizie. Część II. Oksydoreduktazy, transferazy, liazy, izomerazy
Applications of enzymes from animal tissues in organic synthesis, Part 2
Autorzy:
Hibner, H.
Ostaszewski, R.
Powiązania:
https://bibliotekanauki.pl/articles/172018.pdf
Data publikacji:
2011
Wydawca:
Polskie Towarzystwo Chemiczne
Tematy:
enzymy zwierzęce
biokataliza
synteza organiczna
zastosowania enzymów
animal enzymes
biocatalysis
organic synthesis
application of enzymes
Opis:
This work shows systematically known types of animal enzymes and their applications in synthesis of pharmaceuticals and nonracemic organic compounds. It lays out similarities in procedures of isolation and purification of particular enzymes. Such procedures usually are so simple that they can be used in every industrial or research laboratory. Most animal enzymes are well-investigated and their structures and substrate specificity are known. They are used as biocatalysts in many chemical processes. Others were used in one or a few reactions but their natural substrates and biochemical properties are described. Trials of predicting potential applications of such enzymes and other substrates for them were performed. Typical applications of: – Oxidoreductases: horse liver alcohol dehydrogenase [3–13], lactate dehydrogenase [16–18], glutamate dehydrogenase [19, 20], carbonyl reductase [24], catalase [27]; – Transferases: transaldolase [29], galactosyltransferase [30], UDP-glucuronosyltransferase [31], fucosyltransferase [34], farnesyl diphosphate synthase [35]; – Lyases: DOPA decarboxylase [38, 39], aldolase [42]; – Isomerases: N-acyl-D-glucosamine 2-epimerase [44] were described. Also examples of or recombined [24, 39, 44] enzymes are given in the text. These modifications enhance catalytic properties or reduce costs of using enzymes. In practical applications a biocatalytic effect of enzymes from animal sources is often compared with microbial ones. This text is focused on processes where animal enzymes gave much better results (yield and enantioselectivity) than microorganisms. They are also proper, unlike whole microorganisms, to investigate and computer analysis of mechanism of the reaction. Enzymes isolated from animal tissues usually have well-defined structure of active site which is a key to predict mechanisms. A quantitative analysis of applications of these enzymes was performed. Among animal enzymes hydrolases and oxidoreductases have found the most applications in synthesis. Transferases are also often used. Other classes of enzymes seldom act as biocatalysts. It is general tendency, true also in relation to microbial and plant enzymes.
Źródło:
Wiadomości Chemiczne; 2011, 65, 7-8; 585-607
0043-5104
2300-0295
Pojawia się w:
Wiadomości Chemiczne
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Biokatalityczne metody otrzymywania nieracemicznych alkoholi aryloallilowych
Biocatalytic methods for preparation of nonracemic arylallylic alcohols
Autorzy:
Szymkuć, S.
Ostaszewski, R.
Powiązania:
https://bibliotekanauki.pl/articles/172469.pdf
Data publikacji:
2012
Wydawca:
Polskie Towarzystwo Chemiczne
Tematy:
biokataliza
nieracemiczne alkohole aryloallilowe
synteza organiczna
enzymy
mikroorganizmy
biocatalysis
nonracemic arylallylic alcohols
organic synthesis
enzymes
microorganisms
Opis:
Different methods for preparing nonracemic arylallylic alcohols are presented in this work. A key feature was an application the biocatalyst as a mean to obtain final products. These compounds play an important role in pharmaceutical industry, because they are substrates in the synthesis of various important therapeutics [1–3]. Methods presented in this work are divided into five main groups: 1. enantioselective hydroxylation, 2. microbiological deracemization, 3. enzymatic kinetic resolution, 4. enzymatic dynamic kinetic resolution, 5. enantioselective reduction. First two methods use only microorganisms like bacteria [4, 5, 10], fungi [6–8] or yeasts [11] as biocatalysts. Owing to the metabolic processes in the cells it was possible to obtain nonracemic arylallylic alcohol (results for method 2 are presented in Table 1). Unfortunately, the data were insufficient to create direct correlation between values of enantiomeric excess and types of applied microorganisms. Methods 3 and 4 used only isolated enzymes as biocatalysts. They belong to two classes: hydrolases and oxidoreductases. Oxidoreductases were used in the enzymatic kinetic resolution based on the enantioselective oxidation [28] of one enantiomer of the racemic arylallylic alcohol. Nevertheless, hydrolases [12–27], mainly lipases, isolated from microorganisms are enzymes of common use in enzymatic kinetic resolution. Owing to this method it was possible to obtain final products with excellent enantioselectivity (results are presented in Tables 2 and 3). Because kinetic resolution and dynamic kinetic resolution are related processes, in most cases similar enzymes are used. The choice of lipases as biocatalysts for method 4 was caused by the fact that they are able to catalyze enantioselective transesterification of arylallylic alcohols or their acetates. Furthermore, racemization is very important factor for efficacy of dynamic kinetic resolution processes. In most cases they are catalyzed by different types of complexes based on palladium [30, 31] and ruthenium [32, 34]. Final products prepared by this method had very high enantiomeric excesses and yields up to 93% (results are presented in Tables 4 and 5). The only method, presented in this work, that allowed to use both enzymes [39–41] and microorganisms [35–38] as biocatalysts, was enantioselective reduction. This method allows to obtain nonracemic arylallylic alcohols with excellent enantiomeric excess and yields up to 85% (results are presented in Table 6). In summary, all methods presented in this work show the advantages of biocatalysis as an alternative route to traditional chemical method
Źródło:
Wiadomości Chemiczne; 2012, 66, 1-2; 93-118
0043-5104
2300-0295
Pojawia się w:
Wiadomości Chemiczne
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Biocatalytic reduction of ketones in a secondary school laboratory
Biokatalityczna redukcja ketonów w laboratorium szkoły średniej
Autorzy:
Lacušková, D.
Drozdíková, A.
Powiązania:
https://bibliotekanauki.pl/articles/106478.pdf
Data publikacji:
2017
Wydawca:
Towarzystwo Chemii i Inżynierii Ekologicznej
Tematy:
biocatalysis
green chemistry
enzymes
school experiment
semi-structured interview
biokataliza
zielona chemia
enzymy
eksperyment szkolny
wywiad półustrukturyzowany
Opis:
Biocatalysis is one of the most important industrial methods which has been increasingly attracting attention of scientists as a new and environmentally acceptable method. It is used in the preparation of chiral alcohols - important building blocks for the synthesis of fine chemicals, pharmaceuticals, agrochemicals and analogues of natural substances. In biocatalysis the use of traditional chiral agents based on heavy metals has been replaced by the use of enzymes. In many cases, the number of reaction steps has been limited, the selectivity of the desired products has been increased while the negative impact on the environment has been reduced. The principles of biocatalysis have been applied by us to design a simple chemical experiment for the students of higher secondary education. The modified assignment of a lab task consisted of bioreduction of 4-nitroacetophenone using the enzymes present in plant tissues of carrot, parsley and white radish. Within our pedagogical research, the adequacy of the chemical experiment for secondary school students was examined and the extent of understanding of the green chemistry experiment was analysed by the method of a semi-structured interview.
Biokataliza jest jedną z najważniejszych metod przemysłowych, która w coraz większym stopniu przyciąga uwagę naukowców jako metoda nowa i akceptowalna dla środowiska. Stosuje się ją do wytwarzania chiralnych alkoholi - ważnych cegiełek do syntezy wysokowartościowych chemikaliów, farmaceutyków, agrochemikaliów i analogów substancji naturalnych. W biokatalizie stosowanie tradycyjnych związków chiralnych na bazie metali ciężkich zostało zastąpione przez wykorzystanie enzymów. W wielu przypadkach liczba etapów reakcji została ograniczona, selektywność pożądanych produktów została zwiększona, a negatywny wpływ na środowisko został zmniejszony. Zasady biokatalizy zostały przez nas zastosowane w celu zaprojektowania prostego eksperymentu chemicznego dla uczniów szkół średnich II stopnia. Zmodyfikowane ćwiczenie laboratoryjne polegało na bioredukcji 4-nitroacetofenonu za pomocą enzymów obecnych w tkankach roślinnych marchwi, pietruszki i białej rzodkwi. W ramach naszych badań pedagogicznych przeanalizowano adekwatność eksperymentu chemicznego dla uczniów szkół średnich, a zrozumienie doświadczenia z zakresu zielonej chemii zostało zbadane za pomocą wywiadu półustrukturyzowanego.
Źródło:
Chemistry-Didactics-Ecology-Metrology; 2017, 22, 1-2; 123-133
2084-4506
Pojawia się w:
Chemistry-Didactics-Ecology-Metrology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Biocatalytic ketone reduction - a study on screening and effect of culture conditions on the reduction of selected ketones
Autorzy:
Kuncham, R.
Gurumurthy, K.T.
Chandan, N.
Javed, A.
Ashwini, L.S.
Shenoi, R.
Baranwal, A.
Powiązania:
https://bibliotekanauki.pl/articles/11870.pdf
Data publikacji:
2014
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
biocatalysis
ketone reduction
screening
culture condition
Aspergillus ochraceus
Aspergillus flavus
Aspergillus tubingenesis
Aspergillus niger
Rhizopus stolonifer
baker's yeast
enzyme activity
enzyme expression
bioconversion
Opis:
Microbial conversions are gaining importance in the synthesis of important drug metabolites and their intermediates as they are good alternative to chemical synthesis since they are enantio-selective and regio-selective and even can be carried out at ambient temperature and atmospheric pressure. Till date, biocatalytic reduction of acetophenone and its derivatives has been widely reported. In the present study, we have made an attempt to carry out the microbial bioreduction of o-hydroxyacetophenone by screening some of the selected microorganisms which were obtained from culture collection centre as well as those which are isolated in our Microbiology lab. The selected microorganisms include Aspergillus ochraceous, Aspergillus flavus, Aspergillus tubingenesis, Aspergillus niger, Rhizopus stolanifer MTCC 162, Rhizopus stolanifer MTCC 2591 and Baker’s yeast.Among the seven microorganisms screened for the bioreduction of o-hydroxyacetophenone, Baker’s yeast and Aspergillus tubingenesis showed significant bioconversion where as Aspergillus ochraceous exhibited the least bioconversion.In our earlier study it was found that Aspergillus flavus has the required bioreductase enzyme, which showed the maximum conversion of p-chloroacetophenone to p-chlorophenylethanol. Hence optimization of culture conditions to get maximum enzyme expression and hence maximum conversion was thought off. The parameters considered for the study include effect of various Carbon sources, Nitrogen source, Metal ions, incubation Temperature and media pH on enzyme expression. The optimized culture a condition at which maximum bioconversion was achieved was maltose among various carbon sources. Tryptone was found to have maximum effect among the nitrogen sources. Media pH 7.6 and incubation temperature of 35 °C was found to be favourable for maximum enzyme activity. Among various divalent metal salts, addition of magnesium sulphate to the media significantly increased the enzyme activity.
Źródło:
International Letters of Natural Sciences; 2014, 01
2300-9675
Pojawia się w:
International Letters of Natural Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Przemysłowe zastosowania lipaz w syntezie związków o wysokiej wartości dodanej – 85 lat katalizy enzymatycznej lipazami. Część 1
Industrial applications of lipases in the synthesis of high added-value chemicals – 85 years of lipase-based enzymatic catalysis. Part 1
Autorzy:
Borowiecki, P.
Powiązania:
https://bibliotekanauki.pl/articles/171564.pdf
Data publikacji:
2015
Wydawca:
Polskie Towarzystwo Chemiczne
Tematy:
lipazy
lipaza B Candida antarctica
CAL-B
lipaza Burkholderia cepacia
BCL
zastosowania przemysłowe
biokataliza
związki enancjomerycznie czyste
Candida antarctica lipase B
Burkholderia cepacia lipase
industrial applications
biocatalysis
enantiomerically pure compounds
Opis:
Lipases (EC 3.1.1.3; triacylglycerol acylhydrolases) are the most commonly used enzymes in biotransformations of organic compounds. In living organisms lipases catalyze hydrolysis of higher fatty acid esters of glycerol, thus fulfill an essential function in metabolism of lipids (e.g. fats and oils) and lipoproteins. This year marks 125 years since J.R. Green has identified and described the first lipase isolated from germinated castor-oil beans (Ricinus communis L.) in the form of an extract showing hydrolytic properties. Plants, as well as bacteria are able to produce lipases what was reported in 1901 by Dutch scientist ‒ Christiaan Eijkman. Lipases are also produced by fungi, yeasts, and various organs of higher organisms. A strong foundation, which had a huge impact on the development of global lipase-mediated biotransformations was the discovery made in 1935 and described in Biochemistry Journal and Biochemische Zeitschrift by Polish biochemist- -enzymologist Ernest Alexander Sym (1893-1950) that these enzymes retain almost full catalytic activity even in nearly anhydrous organic solvents. This was exactly fifty years before Russian chemist Alexander Klibanov in 1985 described a lipase- -catalyzed reaction carried out in organic solvents. Since that moment, lipases have became extremely popular in both academic and industrial usage, nowadays being the most important among all biocatalysts used in biochemical processes carried out on an industrial scale. The purpose of this article is to provide a brief characterization of the two most widely used in industrial biotransformations lipases ‒ lipase B from Candida antarctica (CAL-B) and lipase from Burkholderia cepacia (BCL) ‒ and familiarize the readers with the issues of biotechnological processes catalyzed by them. The specifics of a range of industrial applications based on lipase catalysis, including the chemical, pharmaceutical, cosmetic and food industries are also discussed. Keywords:
Źródło:
Wiadomości Chemiczne; 2015, 69, 5-6; 391-430
0043-5104
2300-0295
Pojawia się w:
Wiadomości Chemiczne
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-15 z 16

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